I've never seen a bass clef for tenors. However, in choral works the tenors are frequently reading the bass clef. It is a pretty safe bet that recorder ensembles sometimes read choral sheet music. When this happens how do you deal with the bass clef issue for the tenors?
Of course, the bottom note on the tenor would have to be written as bass clef C, in order that the tenor and bass will match up in the proper voicing.
Has anyone here ever pondered this seemingly-important question?
I guess I'm not sure what you mean by a bass clef for tenors. If I have to play something written in bass clef while I'm playing a tenor, I read in bass clef and play it on a tenor. Do you mean you're rewriting it somehow?
By "notation" I'm thinking mainly in terms of written octave positioning. In treble clef, sopranos read an octave below pitch but altos and tenors read at pitch. In bass clef, F-bass and great bass read an octave below pitch but contrabass and, I assume, sub-contrabass read at pitch.
So it would make sense that if a tenor recorder was reading bass clef, the instrument's bottom C would be written in the third space (one octave below real pitch), with ledger lines above the staff being used from midrange C on up through the second octave - kind of like the higher notes on a cello, bassoon or trombone part.
Whisk, since you indicated that you do occasionally read bass clef music, certainly you should know the answer to this one. The 8va notation is the only one that makes sense to me.
When I read bass clef while I'm playing a tenor, I read the c that sits in the second space from the bottom line as being the lowest c on my recorder, which sounds like what you were describing. Is that what you were asking?
The most beautiful thing about recorders is something they share with flutes and violins (and is something I miss when I play clarinet). You can read any music you want. Much recorder music is written without the instrument being specified. The players look over the range of notes and decide which recorder to use on each part. People who play bass recorder can usually play music in both common clefs. So, you can play tenor recorder from reading any clef you know. You read in whichever octave you need to. When you see the lowest C in the piece, you play the lowest C on your instrument.